Mining machine with control and operating system for mining head and traction means



MINING MACHINE WITH CONTROL AND OPERATING SYSTEM FOR MINING.

HEAD AND TRACTION MEANS 2 Sheets-Sheet 1 Filed March 25, 1968 /NVEN.TOE,'

' BY q TTOR/VEYZ I ARTHUR L..Cn.ues,

March 3, 1970 I A. L. CILLES MINING MACHINE WITH CONTROL AND OPERATING SYSTEM FOR MINING".

HEAD AND TRACTION MEANS 2 Sheets-Sheet 2 v //v\/E/v7'0/?; ARTHUR L.CILL.ES, iTTOL/YEX Filed March 25, 1968 United States Patent Int. Cl. E21c 25/00 US. Cl. 299-64 25 Claims ABSTRACT OF THE DISCLOSURE A mining machine with a mining head that is positioned at the top of the mine face, and then is advanced into the mine face and traversed downwardly through the mine face to cut and break the material out of the mine face. The mining machine is supported on traction treads by which the machine is propelled forwardly to advance the mining head into the mine face. The mining machine has a system to control and operate the mining head and traction means with a single main or primary control device for the several functions of the mining head and the traction means.

The instant invention relates to mining machines, and I more particularly to an improved control and operating system for the mining head and traction means of the mining machine.

Mining machines of the continuous type are usually mobile machines that include traction means on which the machine is supported and by which the machine may be propelled. At the forward end of the machine there is a mining head which is advanced into the mine face to 0 cut and break the material out of the mine face. Such material is collected by gathering means, also at the forward end of the machine, which sweeps the material onto a conveyor which extends from the forward end to the rear end of the machine to discharge the mined material to a car or other conveyance that carries the material away from the mining place.

In one form of continuous mining machine the mining head has a transverse cutting and breaking element, somewhat of a cylindrical form with circumferentially disposed cutting bits, which is rotated during the mining operation. The mining head is advanced into the material at the top of the mine face, and then the mining head is moved downwardly to the mine floor, cutting and breaking the material out of the mine face as it moves downwardly. The mining head may be mounted on a boom with which the mining head is moved upwardly and downwardly as may be required for the mining operation. The traction means of the machine is used to propel the machine forwardly to advance the mining head into the mine face, and then the traction means is stopped to hold the mining machine in fixed position as the mining head is moved downwardly to cut and break the material out of the mine face down to the mine floor.

It is necessary to control the rate of advance of the mining head into the material of the mine face, since the material may offer greater or lesser resistance to the mining head, depending on the character of the material in the mine face. Therefore, the speed of operation of the traction means is adjusted to give the best rate of advance of the mining head into the material. Similarly, the rate of descent of the mining head during the cutting and breaking of the material in the mine face must be controlled in accordance with the resistance of the material to the cutting and breaking action of the mining head. Since the cutting and breaking operation is usually performed from the top to the bottom of the mine face, the

3,498,676 Patented Mar. 3, 1970 movement of the mining head to the top of the mine face to position it for the next cutting and breaking stroke is usually an idle or nonproductive stroke. Therefore, the elevation or raising movement of the mining head to the top of the mine face in preparation for the next cutting and breaking stroke should be performed as quickly as possible in order to minimize the time for this idle operation.

' It is an object of this invention to provide an improved control and operating system for the traction means and mining head in a mining machine.

It is another object of this invention to provide an improved control and operating system for the traction means and mining head in a mining machine, in which these mechanisms may be operated and controlled by means of a single control element.

It is a further object of this invention to provide an improved control and operating system for a mining machine in which the speed of operation of the traction means may be adjusted to control the rate of advance of the mining head into the material of the mine face in accordance with the resistance of the material to the mining head.

It is also an object of this invention to provide an improved control and operating system in a mining machine in which the rate at which the mining head is traversed through the mine face to cut and break the material from the mine face may be controlled in accordance with the resistance of the material to the mining head.

It is still another object of the instant invention to provide an improved control and operating system for a mining machine in which the mining head may be quickly moved to position it for the next traverse of the mining head through the material of the mine face.

It is still another objection of the instant invention to provide a hydraulic control and operating system for the mining head and the traction means in a mining machine, in which the functions and operations of these elements are controlled by several control valves which in turn are controlled by a common selective control valve, such that the mining head and traction means of the mining ma-' chine may be controlled in their functions and operations by a single control element.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the drawings:

FIG. 1 is a side elevational view of a mining machine which embodies this invention;

FIG. 2 is a plan view of the mining machine shown in FIG. 1; and

FIG. 3 is a diagram of the controland operating system for the mining bead and traction means of the mining machine.

Referring to FIGS. 1 and 2, there is illustrated a mining machine 10 supported on endless crawler traction treads 11, 11 disposed one at each side of the machine 10, and by which the latter is propelled. Electric motors 12, 17 are disposed one at opposite sides of the mining machine 10 and provide the power for driving the elements of the mining machine 10. At one side of the machine 10 the motor 12 is connected by a universal connected shaft 13 to a gear transmission 14 that drives a hydraulic pump 15 for pilot hydraulic fluid and a hydraulic pump 16 which provides a variable volume supply of hydraulic fluid. At the other side of the mining machine 10 the motor 17 also drives a universal connected shaft 18 which drives a gear transmission 19. The gear transmissions 14, 19 are connected to further gear transmissions 20, 21, respectively, to drive the traction treads 11, 11 at either an intermediate speed or a high speed. There is also provided a hydraulic motor 22, which is used to drive the traction treads 11, 11 at a low speed, and the hydraulic pump 16 supplies hydraulic fluid for the motor 22. A double pump 23, 24, which provides two supplies of hydraulic fluid under pressure is also driven from the transmission 19.

At the forward end of the mining machine there is a mining head that is rotatably supported on the end of a boom 26, which is pivotally supported on a common pivot structure 27. Double acting hydraulic cylinders 28, 28 are disposed one at each side of the mining machine 10, and are connected between the main frame 29 and the boom 26. The cylinders 28, 28 are extended to swing the boom 26 and the mining head 25 upwardly on the pivot structure 27, and by contraction of the cylinders 28, 28 the boom 26 and the mining head 25 are swung downwardly on the pivot structure 27. The mining head 25 is driven from the motors 12, 17 through universal shafts 30, 30 which connect to gear transmissions 31, 31, symmetrically disposed at opposite sides of the boom 26.

The mining head 25 has a somewhat cylindrical configuration and is formed with spiral flights 32, 32 which carry a plurality of radially projecting cutting bits 33, 33. Cutting chains 34, 34 carry a plurality of projecting cutting bits 35, 35 and cut clearance for the gear transmissions that lead up to the mining head 25 to drive the latter.

Also at the forward end of the mining machine 10 and below the boom 26, there is a gathering head 36 which is pivotally supported on the common pivot structure 27. Cylinders 37, 37 are connected between the main frame 29 and the gathering head 36 for adjusting the position of the gathering head 36 upwardly and downwardly to maintain the gathering head on the mine floor for most effectively collecting the mined material. The gathering head 36 has gathering arms 38, 38 which are disposed one at each side, and these operate on the apron or deck 39 of the gathering head 36 with a sweeping motion to collect the mined material and to sweep it onto a chain and flight conveyor 40, which moves the material to the rear of the mining machine 10 to be discharged from the conveyor boom 41. The gathering arms 38, 38 and the conveyor 40 are driven from motors 12, 17 by universal connected shafts 42, 42 which connect to mechanical transmissions 43, 43 at the opposite sides of the mining machine 10.

In the operation of the mining machine 10, the traction treads 11, 11 are usually operated at the intermediate speed to move the mining machine 10 up to the mine face. Then the boom 26 is raised by cylinders 28, 28 to position the mining head 25 at the top of the mine face. Since this is an idle or nonproductive movement of the mining head 25, it is desired to move the mining head 25 quickly, so as to minimize this nonproductive time. Then the mining machine 10 is propelled forwardly by operation of the traction treads 11, 11 at their low speed to advance the mining head 25 into the mine face. During this time the mining head 25 is operating and is cutting and breaking the material out of the mine face as it advances. The hydraulic motor 22 is used for operating the traction treads 11, 11 in their low speed, and the speed of the motor 22 may be adjusted in the low speed range to control the speed of the traction treads 11, 11 according to the resistance of the material to the cutting and breaking operation of the mining head 25.

When the mining head 25 has been advanced into the mine face to the desired depth, the operation of the traction treads 11, 11 is stopped and then the cylinders 28, 28 are contracted to traverse the mining head 25 through the material of the mine face by moving it downwardly towards the mine floor. As the material is cut and broken out of the mine face, it falls to the mine floor and is collected by the gathering arms 38, 38 which sweep the material onto the conveyor 40 to be discharged at the rear of the mining machine 10. The spiral flights 32 of the mining head 25 move the material towards the longitudinal center line of the machine 10 which provides an assist for the gathering arms 38, 38.

FIG. 3 is a diagram of the control and operating system for the traction treads 11, 11 and the mining head 25. There is a common selective control valve 45 which is the main or primary control element and it has four positions for controlling the traction treads 11, 11 boom 26 and the mining head 25. A pump 15 supplies hydraulic fluid under pressure to the valve 45 through a line 47 and a line 48. The line 47 connects to a relief valve 49 which controls and limits the maximum pressure of the hydraulic fluid in the line 47. A relief valve is connected to the line 48 to control and limit the maximum pressure of the hydraulic fluid in the line 48. By way of example, the relief valve 49 may be set for a pressure of 500 p.s.i., and the relief valve 50 is set for a lower pressure, which may be 300 p.s.i. The hydraulic fluid in line 47 may be used to supply other hydraulic elements in the machine. The line 48 is connected to the common selective control valve 45 to supply pilot hydraulic fluid to the valve 45 from the pump 15.

The common selective control valve 45 is manually operated with a spring return to its first position. The line 48 is blocked in the first position of the control valve 45, and the hydraulic fluid may discharge through relief valve 50 to tank. Hydraulic lines 51, 52, 53 are connected to the control valve 45, and are connected to tank through the valve 45 in the first position of the latter.

There are several secondary control valves, the operations of which are governed by the common selective control valve 45. The first secondary control valve 55 is a two position valve which is normally in the lower position, as viewed in FIG. 3, and is pilot operated to its upper position by hydraulic pilot 67 under control of the valve 45. The valve 55 has a spring return to its first position. A variable volume pump 16 is connected to valve 55 by line 57, and then to line 58 to supply hydraulic fluid to the hydraulic motor 22. The variable volume pump 16 has a servo control 59 which is connected by a cable 60 to the manual operator 46 of the control valve 45. The valve 45 includes a spool which may be shifted longitudinally by the manual operator 46 to set the valve 45 in any one of its four positions. The manual operator 46 may also be moved transversely, to the cable 60, which sets the position of the servo control 59 to adjust the volume rate of supply of the variable volume pump 16.

The speed of the motor 22 is governed by the volume rate of supply of hydraulic fluid from the pump 16. A relief valve 61 is connected to the line 58 to limit the maximum pressure of the hydraulic fluid to the motor 22. A line 62 connects the relief valve 61 to tank. The line 57 is also connected through the valve 55 to a line 63 which connects to a relief valve 64, which also operates to limit the maximum pressure of the hydraulic fluid in the lines 57, 58. A line 65 connects from the relief valve 64 to the tank line 62. Thus, in the first position of the control valve 45, the traction treads 11, 11 are operated at a selected speed in the low speed range of operation to propel the mining machine 10 forwardly to advance the mining head 25 into the mine face.

The second position of the control valve 45 is used to move the boom 26 with the mining head 25 upwardly to position the latter at the top of the mine face prior to its advance into the mine face. In the second position of the control valve 45 the line 48 is connected through the valve 45 to line 52, and the lines 51, 53 are connected through the control valve 45 to tank. A pilot line 68 is connected to the line 52 and to one end of the shuttle valve 69 to move the latter to its left position, as viewed in FIG. 3, to connect line 52 to line 70 through the valve 69. The line 70 is connected to the hydraulic pilot 67 of first secondary control valve 55 to move the latter to its upper position, as viewed in FIG. 3. A line 71 is connected to line 52 and to hydraulic pilot 72 of second secondary control valve 73 to move the latter to its lower position, as viewed in FIG. 3.

When valves 55, 73 are set, as stated above, the boom 26 and the mining head 25 may be raised by extension of the cylinders 28, 28. The line 57 is connected through valve 55 to line 63 and line 74 to line 75. The relief valve 64 operates to limit the maximum pressure of the hydraulic fluid in the lines 63, 74, 75. The line 75 connects through valve 73 to line 76, which connects to counterbalance valve 77 that includes check valve 78. The hydraulic fluid flows past the check valve 78 to line 79 and to line 80 to supply the lower ends of the cylinders 28, 28 and to extend the latter. The speed at which the cylinders 28, 28 are extended may be adjusted within the supply limits of the variable volume pump 16.

As the cylinders 28, 28 are extended, hydraulic fluid is forced out of the upper ends of the cylinders 28, 28 and discharged through line 81 which connects to line 82, connected through the second secondary control valve 73 to line 83 and to tank line 62.

The speed at which the cylinders 28, 28 are extended and the mining head 25 raised may be substantially increased by moving the common selective control valve 45 to its third position, which introduces additional supply of hydraulic fluid above the maximum rate of supply from the first pump 16.

In the third position of the control valve 45, the line 48 is connected through the valve 45 to the line 52 in the same manner and with the same resultant operation as described above with respect to the second position of the control valve 45. There is an additional connection from the line 48 through the control valve 45 to the line 53, which is connected to the lines 85, 86. The line 85 is connected to the hydraulic pilot 87 of the third secondary control valve 88 to move the latter to its lower position, as viewed in FIG. 3. The second pump 23 is connected by line 91 to valve 88, and in the lower position of the latter the line 91 is connected through the valve 88 to line 92 which connects to line 75 to the second secondary control valve 73. The line 91 also connects through the valve 88 to line 93 and to relief valve 94, which limits the maximum pressure of the hydraulic fluid in the lines 91, 92. The relief valve 94 is connected by line 95 to tank line 62.

The line 86 is connected to hydraulic pilot 96 of the fourth secondary control valve 97 to move the latter to its lower position, as viewed in FIG. 3. The third pump 24 is connected to lines 99, 100, 101, through check valve 102 and line 103 to connect through valve 97 to line 104 which is connected to line 80, to supply hydraulic fluid to the lower ends of cylinders 28, 28 to extend the latter. A relief valve 105 is connected to lines 99, 100 to limit the maximum pressure in these lines, and line 106 connects from relief valve 105 to tank. Return hydraulic fluid from the upper ends of cylinders 28, 28 flows through line 81, and a portion of this return flow may now flow through line 107 which is connected to line 81, and line 107 connects through valve 97 to line 108 which connects to line 106 and to tank. The check valve 102 blocks reverse flow of hydraulic fluid from the lower ends of the cylinders 28, 28, which holds the boom 26 and the mining head 25 until the pressure of the hydraulic fluid builds up from pump 24, and also holds the boom 26 and the mining head 25 in the event of a failure of any of the pump 24, the relief valve 105 or lines 99, 100, 101.

Summarizing the foregoing, in the third position of the common selective control valve 45, the hydraulic fluid from the first pump 16 is supplied through the first secondary control valve 55 to the second secondary control valve 73, the latter being set in its lower position, as viewed in FIG. 3, for extending the cylinders 28, 28. The hydraulic fluid from the second pump 23 is supplied through the third secondary control valve 88 to the second secondary control valve 73, so that the hydraulic fluid from the pumps 16, 23 are combined at the control valve 73. Such combined hydraulic fluid is ultimately supplied through line 80 to the lower ends of the hydraulic cylinders 28, 28. The hydraulic fluid from the third pump 24 is supplied through the fourth secondary control valve 97, which is set in its lower position, to the line 80 where this hydraulic fluid combines with the hydraulic fluid from the pumps 16, 23, such that the total combined hydraulic fluid is supplied to the lower ends of the cylinders 28, 28 to extend the latter at a high speed, which raises the boom 26 and the mining head 25 in minimum time.

When the common selective control valve 45 is moved from its third position to its second position, the third secondary control valve 88 and the fourth secondary control valve 97 are spring returned to their initial positions. In the initial position of the valve 88, pump 23 is connected by line 91 through valve 88 to line 110 which connects to tank line 62. Line 91 is also connected through valve 88 to line 93 which connects to relief valve 94 for limiting the maximum pressure in line 91. In the initial position of the fourth secondary control valve 97 the third pump 24 is connected by line 99 through valve 97 to line 111, and through a manual control valve 112 to line 113, which is connected to tank.

When the common selective control valve 45 is moved from its second position to its first position, the second secondary control valve 73 is spring returned to its neutral or centered position, and the first secondary control valve 55 is also spring returned to its initial position. The first pump 16 is thus disconnected from the cylinders' 28, 28. When the mining head 25 has been placed at the desired elevation to be advanced into the mine face, and with the common selective control valve 45 in its first position, the variable volume pump 16 may be adjusted by the servo 59 to provide the desired supply rate of hydraulic fluid to the hydraulic motor 22, through the valve 55, for operating the motor 22 and the traction treads 11, 11 to advance the mining head 25 into the mine face. This is continued until the mining head 25 has been advanced into the mine face to the desired depth of penetration.

The next operation is that of moving the boom 26 and the mining head 25 downwardly in a traverse of the mine face to cut and break the material out of the mine face. The common selective control valve 45 is moved to its fourth position in which the supply line 48 is connected through the valve 45 to the line 51. The lines 52, 53 are connected through the valve 45 to tank. The line 51 is connected to pilot line 115 which moves the shuttle valve 69 to its right position, as viewed in FIG. 3, to connect line 51 through the shuttle valve 69 to line 70, which connects to the hydraulic pilot 67 of the first secondary control valve 55 to move the latter to its upper position, as viewed in FIG. 3, for the supply of hydraulic fluld from the first pump 16 through the valve 55 to the second secondary control valve 73. The line 51 connects also to the hydraulic pilot 116 of the second secondary control valve 73 to move it to its upper position, as viewed in FIG. 3, in which line 75 connects through valve 73 to line 82 which connects to line 81 to supply hydraulic fluid to the upper ends of the cylinders 28, 28 to contract the latter. The counterbalance valve 77 opposes the return flow of hydraulic fluid from the lower ends of the cylinders 28, 28. Therefore, the cylinders 28, 28 must be driven down by the supply hydraulic fluid against the back pressure that is provided by the counterbalance valve 77. This permits a controlled rate of descent or lowering of the mining head 25 as it is traversed in the mine face. The return hydraulic fluid flows through lines 80, 79 to counterbalance valve 77, in which the hydraulic fluid in pilot line 89 opens pressure responsive valve to permit flow through the counterbalance valve 77, and then through line 76 through valve 73 to line 83 which connects to tank line 62.

The manual valve .112 may be operated to drop the boom 26 and the mining head 25 without power. The manual valve 112 is moved to its upper position, as viewed in FIG. 3, and the weight of the boom 26 and the mining head 25 is transmitted through the piston rods and pistons to the fluid in the lower ends of the cylinders 28, 28 to cause such fluid to flow out of the cylinders 28, 28 through lines 80, 123 through the valve 112 to line 124 to discharge into tank.

As another function, the boom 26 and the mining head 25 may be moved downwardly against the mine floor, with the effect of raising the front end of the mining machine 10 off the mine floor. The purpose is to provide access to parts of the mining machine 10 for repairs or service, as may be needed. The common selective control valve 45 is moved to its fourth position, and the manual valve 112 is moved to its upper position, as viewed in FIG 3. In this operation the first pump 16 supplies hydraulic fluid through the second secondary control valve 73, and the third pump 24 is used to supply hydraulic fluid through the manual valve 112. The hydraulic fluid flows from third pump 24 through lines 99, .100, through check valve 121 and line 122, through valve 112, through lines 118, 81 to the upper ends of the cylinders 28, 28. The second secondary control valve 73 is in its upper position, as viewed in FIG. 3. The variable volume pump 16 supplies hydraulic fluid through valve 73 to lines 82, 81 and the hydraulic fluid from both sources combines and exerts pressure in the upper ends of the cylinders 28, 28. The return flow of hydraulic fluid from the lower ends of the cylinders 28, 28 is through lines 80, 123 to the manual valve 112, and then through line 124 to tank.

The relief valve 125 is connected by line 126 to line 118 and has the effect of limiting the maximum pressure in lines 118, 81, which are connected to the tops of the cylinders 28, 2-8. This prevents an excessive buildup of pressure in the upper ends of the cylinders 28, 28 in the event of an inadvertent raising of the boom 26 and the mining head 25. Line 127 connects the relief valve 125 to tank.

The second secondary control valve 73 in its neutral or centered position is connected to tank by lines 83, 62 in one direction and by line 84 in the other direction through third secondary control valve 88 to line 95 and tank line 62. The counterbalance valve 77 resists the weight of the boom 26 and the mining head 25 which produce a downward force on the cylinders 28, 28 tending to contract the latter and to force hydraulic fluid out of the lower ends of the cylinders 28, 28. However, in the event of a roof fall on the boom 26 and the mining head 25, or another excessive force bearing downwardly, such force would exceed the upper limit of the counterbalance valve 77, and the latter would then open to permit flow through the counterbalance valve 77 and through line 76 to valve 73, and through lines 83, 62 to tank. This is a safety feature which protects the elements of the mining machine 10 in the event of an excessive force bearing downwardly on the boom 26 and the mining head 25.

The control and operating system which is described above provides control of the traction treads 11, 11 and of the boom 26 and mining head 25 from a single main or primary control element which is the common selective control valve 45. The operator of the machine has only the one element to be operated for the performance of the mining operation with the mining head 25 to cut and break the material out of the mine face. This includes the operations of moving the mining head 25 upwardly to position it at the top of the mine face, then advancing the mining head 25 into the mine face by means of traction treads 11, 11, and then traversing the mining head 25 downwardly through the mine face, cutting and breaking the material out of the mine face to be collected by the gathering arms 38, 38 and moved to the rear of the mining machine 10 by the conveyor 40.

Having thus described and shown an embodiment of the invention, what it is desired to secure by Letters Patent of the United States is:

1. A mining machine for cutting and breaking material from a mine face comprising, a cutting and breaking means at the forward end of the mining machine which is adapted to be traversed in the mine face for cutting and breaking the material therefrom, means for moving said cutting and breaking means upwardly or downwardly to position the cutting and breaking means relatively to the mine face or to traverse the cutting and breaking means in the mine face in a cutting and breaking stroke, means for advancing said cutting and breaking means into the mine face, and common selective control means to control the operation of each of said moving means and said advancing means to selectively move said cutting and breaking means upwardly or downwardly or to advance said cutting and breaking means into the mine face, said means to move the cutting and breaking means comprises a first hydraulic power means that is extensible and retractible to move the cutting and breaking means upwardly and downwardly, means to connect said first hydraulic power means to said cutting and breaking means, said advancing means comprises a second hydraulic power means, hydraulic power supply means for said first and second hydraulic power means, a hydraulic control valve that is connected to said hydraulic power supply means and including said common selective control means to selectively control said hydraulic power supply means to said first hydraulic power means and to said second hydraulic power means, supplemental hydraulic power supply means for said first hydraulic power means, said hydraulic control valve is connected to said supplemental hydraulic power supply means and including said common selective control means to selectively control the supplemental hydraulic power supply means to combine it with the first said hydraulic power supply means to said first hydraulic power means for moving the cutting and breaking means at a higher speed, the first said hydraulic power supply means includes adjustable means to vary the rate of power supply from zero to a maximum rate, and means to connect said common selective control means to said adjustable means to control the rate of power supply of the first said hydraulic power supply.

2. A mining machine for cutting and breaking material from a mine face comprising, a cutting and breaking means at the forward end of the-mining machine which is adapted to be traversed in the mine face for cutting and breaking the material therefrom, means for moving said cutting and breaking means upwardly or downwardly to position the cutting and breaking means relatively to the mine face or to traverse the cutting and breaking means in the mine face in a cutting and breaking stroke, means for advancing said cutting and breaking means into the mine face, and common selective control means to control the operation of each of said moving means and said advancing means to selectively move said cutting and breaking means upwardly or downwardly or to advance said cutting and breaking means into the mine face, said advancing means includes a hydraulic motor, primary hydraulic fluid power supply means, a first secondary control valve for directing hydraulic fluid from said primary supply means to said hydraulic motor, means to connect said first secondary control valve to said hydraulic motor and to said primary supply means, and means to connect said common selective control means to said first secondary control valve to selectively control the operation of the first secondary control valve, said hydraulic motor is fixed volume, said primary hydraulic fluid power supply means is variable volume, means to adjust the volume of said primary power supply means in order to vary the rate of supply of hydraulic fluid and to vary the rate of operation of said hydraulic motor.

3. A mining machine as recited in claim 2, said common selective control means including means to operate said adjusting means for said primary power supply means, and means to connect said operating means to said adjusting means.

4. A mining machine as recited in claim 2, said primary power supply means comprising a variable volume hydraulic pump, a servo device for adjusting the volume rate of delivery of hydraulic fluid for said pump, a mechanical connection from said common selective control means to said servo device to adjust the servo device according to the selected rate of delivery of hydraulic fluid and the servo device adjusting the hydraulic pump for such rate of delivery of hydraulic fluid.

5. A mining machine for cutting and breaking material from a mine face comprising, a cutting and breaking means at the forward end of the mining machine which is adapted to be traversed in the mine face for cutting and breaking the material therefrom, means for moving said cutting and breaking means upwardly or downwardly to position the cutting and breaking means relatively to the mine face or to traverse the cutting and breaking means in the mine face in a cutting and breaking stroke, means for advancing said cutting and breaking means into the mine face, and common selective control means to control the operation of each of said moving means and said advancing means to selectively move said cutting and breaking means upwardly or downwardly or to advance said cutting and breaking means into the mine face, said moving means including hydraulic power means for moving said cutting and breaking means upwardly or downwardly, primary hydraulic fluid power supply means, a first secondary control valve for directing hydraulic fluid from said primary supply means to said hydraulic power means, means to connect said first secondary control valve to said hydraulic power means and to said primary supply means, and means to connect said common selective control means to said first secondary control valve to selectively control the operation of the first secondary control valve, said primary hydraulic power fluid supply means is variable volume, means to adjust the volume of said primary power supply means in order to vary the rate of supply of hydraulic fluid and to vary the rate of operation of said hydraulic power means.

6. A mining machine as recited in claim 5, said common selective control means including means to operate said adjusting means for said primary power supply means, and means to connect said operating means to said adjusting means.

7. A mining machine as recited in claim 5, said primary supply means comprising a variable volume hydraulic pump, a servo device for adjusting the volume rate of delivery of hydraulic fluid for said pump, a mechanical connection from said common selective control means to said servo device to adjust the servo device according to the selected rate of delivery of hydraulic fluid and the servo device adjusting the hydraulic pump for such rate of delivery of hydraulic fluid.

8. A mining machine for cutting and breaking material from a mine face comprising, a cutting and breaking means at the forward end of the mining machine which is adapted to be traversed in the mine face for cutting and breaking the material therefrom, means for moving said cutting and breaking means upwardly or downwardly to position the cutting and breaking means relatively to the mine face or to traverse the cutting and breaking means in the mine face in a cutting and breaking stroke, means for advancing said cutting and breaking means into the mine face, and common selective control means to control the operation of each of said moving means and said advancing means to selectively move said cutting and breaking means upwardly or downwardly or to advance said cutting and breaking means into the mine face, said moving means including hydraulic power means for moving said cutting and breaking means upwardly or downwardly, primary hydraulic fluid power supply means, a first secondary control valve for directing hydraulic fluid from said primary supply means to said hydraulic power means, means to connect said first secondary con- 7 trol valve to said hydraulic power means and to said primary supply means, and means to connect said common selective control means to said first secondary control valve to selectively control the operation of the first secondary control valve, a second secondary control valve connected to said first secondary control valve and to said hydraulic power means for directing hydraulic fluid from the first secondary control valve to the hydraulic power means in one direction to move the cutting and breaking means upwardly or in a second direction to move the cutting and breaking means downwardly, and means to connect said common selective control means to said second secondary control valve to selectively control the operation of the second secondary control valve.

9. A mining machine as recited in claim 8, said hydraulic power means comprising extensible and contractable cylinder means which is extended by said hydraulic fluid in the one direction of the hydraulic fluid and is contracted by said hydraulic fluid in the second direction of the hydraulic fluid.

10. A mining machine as recited in claim 9, including counterbalance valve means connected between said second secondary control valve and said extensible and contractable cylinder means to provide a back pressure of hydraulic fluid to resist movement of the cylinder means.

11. A mining machine as recited in claim 9, including counterbalance valve means having a check valve and a normally closed pressure responsive valve connected between said second secondary control valve and said extensible and contractable cylinder means, said check valve and said pressure responsive valve being connected in parallel for supply flow of hydraulic fluid through the check valve to extend said cylinder means and for return flow of hydraulic fluid in contracting said cylinder means when the pressure of the return flow opens the pressure responsive valve.

12. A mining machine as recited in claim 8, pilot operating means for said second secondary control valve for operating the second secondary control valve to a first position to direct hydraulic fluid to said hydraulic power means in the one direction to move the cutting and breaking means upwardly and for operating the second secondary control valve to a second position to direct hydraulic fluid to said hydraulic power means in the second direction to move the cutting and breaking means downwardly, means to supply pilot hydraulic fluid, said common selective control means including a valve to control the supply of pilot hydraulic fluid to said pilot operating means.

13. A mining machine as recited in claim 12, said sccond secondary control valve including a neutral position intermediate said first position and said second position, spring return means to operate said second secondary con trol valve to its neutral position.

14. A mining machine as recited in claim 8, said primary hydraulic power fluid supply means is variable volume, means to adjust the volume of said primary power supply means in order to vary the rate of supply of hydraulic fluid and to vary the rate of operation of said hydraulic power means.

15. A mining machine as recited in claim 14, said common selective control means including means to operate said adjusting means for said primary power supply means, and means to connect said operating means to said adjusting means.

16. A mining machine as recited in claim 8, a second hydraulic fluid power supply means, a third secondary control valve for directing hydraulic fluid from said sec ond hydraulic fluid power supply means to said hydraulic power means, means to connect said third secondary control valve to said second secondary control valve and to said second supply means, and means to connect said common selective control means to said third secondary control valve to selectively control the operation of the third secondary control valve.

17. A mining machine as recited in claim 16, pilot operating means for said third secondary control valve for operating the third secondary control valve to a second position to direct hydraulic fluid from said second hydraulic fluid power supply means to said hydraulic power means, means to supply pilot hydraulic fluid, said common selective control means including a valve to control the supply of pilot hydraulic fluid to said pilot operating means, spring return means for said third secondary control valve to return the valve to a first position.

18. A mining machine as recited in claim 16, said hydraulic power means comprising extensible and contract able cylinder means which is extended by said hydraulic fluid in the one direction of the hydraulic fluid and is contracted by said hydraulic fluid in the second direction of the hydraulic fluid.

19. A mining machine as recited in claim 16, a third hydraulic fluid power supply means, a fourth secondary control valve for directing hydraulic fluid from said third hydraulic fluid power supply means to said hydraulic power means, means to connect said fourth secondary control valve to said third supply means and to said hydraulic power means, and means to connect said common selective control means to said fourth secondary control valve to selectively control the operation of the fourth secondary control valve.

20. A mining machine as recited in claim 19, pilot operating means for said fourth secondary control valve for operating the fourth secondary control valve to a second position to direct hydraulic fluid from said third supply means to said hydraulic power means, means to supply pilot hydraulic fluid, said common selective control means including a valve to control the supply of pilot hydraulic fluid to said pilot operating means, spring return means for said fourth secondary control valve to return the valve to a first position.

21. A mining machine as recited in claim 19, said hydraulic power means comprising extensible and contractable cylinder means which is extended by said hydraulic fluid in the one direction of the hydraulic fluid and is contracted by said hydraulic fluid in the second direction of the hydraulic fluid.

22. A mining machine as recited in claim 8, a second hydraulic fluid power supply means, a third secondary control valve for directing hydraulic fluid from said secon l 0nd hydraulic fluid power supply means to said hydraulic power means, means to connect said third secondary control valve to said hydraulic power means and to said second supply means, and means to connect said common selective control means to said third secondary control valve to selectively control the operation of the third secondary control valve.

23. A mining machine as recited in claim 22, pilot operating means for said third secondary control valve for operating the third secondary control valve to a second positionto direct hydraulic fluid from said second hydraulic fluid power supply means to said hydraulic power means, means to supply pilot hydraulic fluid, said common selective control-means including a valve to control the supply of pilot hydraulic fluid to said pilot operating means, spring return means for said third secondary control valve to return the valve to a first position.

24. A mining machine as recited in claim 22, a third hydraulic fluid power supply means, a fourth secondary ,control valve for directing hydraulic fluid from said third hydraulic fluid power supply means to said hydraulic power means, means to connect said fourth secondary control valve to said hydraulic power means and to said third supply means, and means to connect said common selective control means to said fourth secondary control valve to selectively control the operation of the fourth secondary control valve.

25. A mining machine as recited in claim 24, pilot operating means for said fourth secondary control valve for operating the fourth secondary control valve to a second position to direct hydraulic fluid from said third supply means to said hydraulic power means, means to supply pilot hydraulic fluid, said common selective control means including a valve to control the supply of pilot hydraulic fluid to said pilot operating means, spring return means for said fourth secondary control valve to return the valve to a first position.

References Cited UNITED STATES PATENTS 968,892 8/1910 Taylor 173-157 2,777,102 l/l957 Barrett 29975 3,002,732 10/1961 Bouille 29976 ERNEST R. PURSER, Primary Examiner I US. Cl. X.R. 9ll78; 173-158; 29976 

